Method of and apparatus for removing scale and expanding boiler flues



Jan. 6. 1925. 1,521,641

' G. R. MAUPIN METHOD OF AND APPARATUS FOR REMOVING SCALE AND EXPANDINGBOILER FLUES Filed Jan. 19, 1922 fa. Z 2

Patented dan. ti, i925.

GRAVES R. MAUPIN, OF MOBERLY, MISSOURI, .ASSG-NR T0 THE J. FAESSLERMANU- i FAGTURING COMPANY, OFTOBERLY, MISSOURI, A COPARTNERSHIP.

METHOD OF AND APPRATUS FOR REMOVING SCALE AND EXANDING- BOILER'FLUES.

v Application fed January 19, 1922. Serial 1\T'o.v 530,456. i

To all whom t may conce-rn.'

Be it known that I, GRAVES R. MAUPIN, a citizen of the United States,and resident of the city of Moberly, county of Randolph, and State ofMissouri, have invented cert-ain new and useful Improvements inMethodsof and Apparatus for Removing Scale and Expanding Boiler F lues,of which the following is a specification containing a full, clear,

and exact description, reference being had to the accompanying drawings,forming a part hereof.

My invention relates to improvements in the method of and apparatus forremoving scale and expanding boiler fines, and has for its primaryobject the method of and apparatus for removing the scale whichaccumulates around a boiler' iiue atits junction with the flue sheet. I

A further object is to construct an apparatus for removing the scale atthe junctior` of a boiler fine and a flue sheet, which apparatus if soconstructed as to exert only radial pressure on the flue-all lateralpressure being imparted to the iiue sheet.

In the drawings,

Fig. 1 is a longitudinal section of my apparatus, showing the same inposition within a boiler flue.

Fig. 2 a side elevation of my improved apparatus with the mandrelremoved.

Fig. 3 an end elevation of the same, looking in the direction of thearrow 3.

y Fig. 4 an end elevation of the same, look ing in the direction of thearrow 4.

Fig. 5 a side elevation of the expander mandrel.

Fig. 6 an end view of the same.

Fig. 7 an enlarged side elevation of one of the expander segments.

Fig. 8 an end view of the same.

In the construction of my device, 9 represents a -flue sheet, and 10 aflue. The iiue sheet is provided with openings 11, in which are seatedcopper gaskets 12. These gaskets being iiush with the outer face of theflue sheet and extending into the boiler. The ends of the flue 10 arereduced in size, as indicated at 13. This reduced portion is inserted inthe gasket 12, so that a por tion of the flue extends through the sheet9. The tube 10 is then expanded within the gasket, so as to form a tightfit between it and the gasket 12, and between the gasket 12 and theopenings 11 formed in the fine sheet, while'they portion oftheiiueimmediately to the rear of the flue sheet 9 is beaded,

las indicated by the numeral 14, as is that portion of the gasket 12 tothe inside lof the flue sheet.v The projecting end of the tube V10 isbeaded over as at 15, thus tightly securing the flue within the sheet.After this joint has beenthus formed, the practice at the present timeis to weld this bead tothe sheet 9, as indicated by the numeral 16. Thisis ldone by what is known as arc welding. After the boiler' has beenusedY a short time, scale will commence to accumulate Abetween thegasket 12 and sheet 9, as indicated by the letter S This scale graduallyextending on to the flue and assumes the shape of a fillet. It is thisscale which my method and apparatus is designed to remove, since the useof boiler compounds does not prevent thc formation Vof scale at thispoint, and if the scale is. not removed, the flues will burn out atvthepoint. My apparatus consists of an expander which is circular in form,and formedv of a plurality of segments 17. These segments are providedon one end with an enlarged cylindrical portion18, which is providedwith a groove 19, and in to Vthis groove 19 is sprung a iiat circularspring 20. This is for the purpose of holding the segments in assembledform. Adjacent the cylindrical portion 1S is a reduced cylindricalportion 21 which is designed to contact with the flue and expan( it inthe flue sheet. The cylindrical portio 21 has an enlarged roundedportion 22 which is adapted to enter the bead 14.

It will be noted from Figs. 3 and 4 that when the segments areVassembled, a polygonal opening is formed therethrough. This openingbeing smaller at the end 23 than at the end 24.

It will also be noted from Fig. 7, that the rear portion which forms theopening in each segment has a greater rinclination than the forwardportion, so that when the mandrel 25 is driven in, it will contact onlywith the forward portionand exert all its pressure there, as there is nopressure needed at the back end of the expanded. The enlargedcylindrical portion 18 is seated within a cage 26. This cage is providedwith three extending feet 27 which rest against the flue sheet justoutside of the weld. This cage is provided with a central opening 28, inwhich the pylindrical portion 18 is located, and the expander is heldwithin the cage by means of the washer 29 which restsv against theshoulder 3() formed in the cage, and this washer is in turn held bymeans of a spring 3l which is seated in a groove 32.

It will be noted that the opening 33 through which the cylindricalportion 2l passes is of larger diameter than the cylindrical portion 21.This is for the purpose of allowing the cage to be so placed that itwill clearall of the welded portion and still allow the expander to beplaced in the iue. In other words, it takes care of any variation ofwidth of metal deposited through the welding. The mandrel 25 is providedwith a tapered portion 34. rIhis tapered portion having a number of flatfaces equal in number tothe number of segments in the expander.

. The operation of my device is as follows:

After the boiler has been in use for a time, the scale S commences toform. Vhen the boiler is to be cleaned, the expander is inserted as inFig. l, and the mandrel 25 inserted through the opening and driven in.This driving in of the mandrel expands the tube or line, thus crackingthe scale, while a certain amount of vibration is imparted to the fluesheet 9 by means of the blows given the mandrel which will jar thescale, previously cracked, loose and dislodge it from the flue sheet andaround the Hue. It will be seen from .this operation, that not only isthe scale removed, but the liuc further tightened in the flue sheet, andduring this operation no lateral pressure is exerted on the flue. Anylateral pressure is transmitted to the flue sheet through the cage 26and feet 27, so that there is no possibility or danger of loosening theflue in the sheet by putting pressure directly against the beaded end 15of the flue.

I-Iaving fully described my invention, what I claim is:

l. The method of removing scale around the tube and inside of the fluesheet of a boiler, which consists in expanding the tube adjacent theflue sheet so as to crack the deposited scale, and simultaneouslytherewith ed tovcontact with the 'flue sheet at points around the flue,said cage adapted to have the expander removably located therein, andremovable means carried by said cage for securing the expander therein,said expander and cage adapted to simultaneously exert an expandingstrain on the Hue and impart vibration to the flue sheet.

In testimony whereof I have signed my name to this specification.

yGreaves a.. Maurin.

